#include <sys/stat.h>
#include <sys/time.h>
#include <fcntl.h>
#include <errno.h>
#include "syscall.h"

#define IS32BIT(x) !((x)+0x80000000ULL>>32)
#define NS_SPECIAL(ns) ((ns)==UTIME_NOW || (ns)==UTIME_OMIT)

int utimensat(int fd, const char *path, const struct timespec times[2], int flags)
{
    int r;
    if (times && times[0].tv_nsec==UTIME_NOW && times[1].tv_nsec==UTIME_NOW)
        times = 0;
#ifdef SYS_utimensat_time64
    r = -ENOSYS;
    time_t s0=0, s1=0;
    long ns0=0, ns1=0;
    if (times) {
        ns0 = times[0].tv_nsec;
        ns1 = times[1].tv_nsec;
        if (!NS_SPECIAL(ns0)) s0 = times[0].tv_sec;
        if (!NS_SPECIAL(ns1)) s1 = times[1].tv_sec;
    }
    if (SYS_utimensat == SYS_utimensat_time64 || !IS32BIT(s0) || !IS32BIT(s1))
        r = __syscall(SYS_utimensat_time64, fd, path, times ?
            ((long long[]){s0, ns0, s1, ns1}) : 0, flags);
    if (SYS_utimensat == SYS_utimensat_time64 || r!=-ENOSYS)
        return __syscall_ret(r);
    if (!IS32BIT(s0) || !IS32BIT(s1))
        return __syscall_ret(-ENOTSUP);
    r = __syscall(SYS_utimensat, fd, path,
        times ? ((long[]){s0, ns0, s1, ns1}) : 0, flags);
#else
    r = __syscall(SYS_utimensat, fd, path, times, flags);
#endif

#ifdef SYS_futimesat
    if (r != -ENOSYS || flags) return __syscall_ret(r);
    long *tv=0, tmp[4];
    if (times) {
        int i;
        tv = tmp;
        for (i=0; i<2; i++) {
            if (times[i].tv_nsec >= 1000000000ULL) {
                if (NS_SPECIAL(times[i].tv_nsec))
                    return __syscall_ret(-ENOSYS);
                return __syscall_ret(-EINVAL);
            }
            tmp[2*i+0] = times[i].tv_sec;
            tmp[2*i+1] = times[i].tv_nsec / 1000;
        }
    }

    r = __syscall(SYS_futimesat, fd, path, tv);
    if (r != -ENOSYS || fd != AT_FDCWD) return __syscall_ret(r);
    r = __syscall(SYS_utimes, path, tv);
#endif
    return __syscall_ret(r);
}
